[BUG] Status bar shows "plan mode on" after plan mode has exited

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

## Bug Description

The status bar UI shows plan mode on even after plan mode has been exited.
The actual system state (via the ## Exited Plan Mode system reminder) correctly
reflects that plan mode ended, but the status bar does not update.

## Steps to Reproduce

1. Enter plan mode (e.g. via a prompt that triggers it)
2. Exit plan mode (ExitPlanMode tool call completes)
3. Observe status bar — still shows plan mode on

## Expected Behavior

Status bar clears plan mode on once plan mode exits.

## Actual Behavior

Status bar continues to show plan mode on despite the system reminder in the
conversation reading: "Exited Plan Mode — You can now make edits, run tools, and
take actions."

## Impact

The model reads the system state correctly and proceeds to take actions (which is
right), but the user sees plan mode on in the status bar and believes the model
is acting out of turn. This creates a contradiction between what the user sees and
what the model does.

## Environment

• Claude Code version: 2.1.112 (latest stable version)
• OS: macOS 25.4.0 (Darwin)
• Shell: zsh

What Should Happen?

When plan mode exits (ExitPlanMode tool call completes and the system emits the "## Exited Plan Mode" reminder), the status bar should immediately clear the "plan mode on" indicator to reflect the current state. The status bar should stay in sync with the actual execution mode so users can trust it as a reliable indicator of what the model is allowed to do.

Error Messages/Logs

Steps to Reproduce

1. Start a session with plan mode enabled (status bar shows "plan mode on")
2. Complete the planning phase — the ExitPlanMode tool is called by the model
3. The system reminder in the conversation shows "## Exited Plan Mode — You can now make edits, run tools, and take actions."
4. Observe the status bar — it still shows "plan mode on" instead of clearing
5. The model proceeds to take actions (correct per system state), but the user sees the stale "plan mode on" indicator and is confused

<img width="1536" height="309" alt="Image" src="https://github.com/user-attachments/assets/090a7713-3de3-4316-8321-92690702f5ff" />

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.112

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

PyCharm terminal

Additional Information

_No response_